chr18-3141986-G-A

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 1P and 4B. PP3BS2

The NM_003803.4(MYOM1):​c.1978C>T​(p.Pro660Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000459 in 1,613,530 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P660A) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 31)
Exomes 𝑓: 0.000049 ( 0 hom. )

Consequence

MYOM1
NM_003803.4 missense

Scores

7
7
5

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 10.0

Publications

6 publications found
Variant links:
Genes affected
MYOM1 (HGNC:7613): (myomesin 1) The giant protein titin, together with its associated proteins, interconnects the major structure of sarcomeres, the M bands and Z discs. The C-terminal end of the titin string extends into the M line, where it binds tightly to M-band constituents of apparent molecular masses of 190 kD (myomesin 1) and 165 kD (myomesin 2). This protein, myomesin 1, like myomesin 2, titin, and other myofibrillar proteins contains structural modules with strong homology to either fibronectin type III (motif I) or immunoglobulin C2 (motif II) domains. Myomesin 1 and myomesin 2 each have a unique N-terminal region followed by 12 modules of motif I or motif II, in the arrangement II-II-I-I-I-I-I-II-II-II-II-II. The two proteins share 50% sequence identity in this repeat-containing region. The head structure formed by these 2 proteins on one end of the titin string extends into the center of the M band. The integrating structure of the sarcomere arises from muscle-specific members of the superfamily of immunoglobulin-like proteins. Alternatively spliced transcript variants encoding different isoforms have been identified. [provided by RefSeq, Jul 2008]
MYOM1 Gene-Disease associations (from GenCC):
  • hypertrophic cardiomyopathy
    Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -3 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.833
BS2
High AC in GnomAdExome4 at 72 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MYOM1NM_003803.4 linkc.1978C>T p.Pro660Ser missense_variant Exon 14 of 38 ENST00000356443.9 NP_003794.3 P52179-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MYOM1ENST00000356443.9 linkc.1978C>T p.Pro660Ser missense_variant Exon 14 of 38 1 NM_003803.4 ENSP00000348821.4 P52179-1
MYOM1ENST00000261606.11 linkc.1978C>T p.Pro660Ser missense_variant Exon 14 of 37 1 ENSP00000261606.7 P52179-2
MYOM1ENST00000577294.1 linkn.34C>T non_coding_transcript_exon_variant Exon 1 of 2 2

Frequencies

GnomAD3 genomes
AF:
0.0000132
AC:
2
AN:
151944
Hom.:
0
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.000956
GnomAD2 exomes
AF:
0.0000321
AC:
8
AN:
249188
AF XY:
0.0000296
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000620
Gnomad OTH exome
AF:
0.000165
GnomAD4 exome
AF:
0.0000493
AC:
72
AN:
1461586
Hom.:
0
Cov.:
30
AF XY:
0.0000536
AC XY:
39
AN XY:
727086
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33476
American (AMR)
AF:
0.00
AC:
0
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26132
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86256
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53388
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5758
European-Non Finnish (NFE)
AF:
0.0000549
AC:
61
AN:
1111796
Other (OTH)
AF:
0.000166
AC:
10
AN:
60362
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.460
Heterozygous variant carriers
0
5
10
14
19
24
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000132
AC:
2
AN:
151944
Hom.:
0
Cov.:
31
AF XY:
0.0000270
AC XY:
2
AN XY:
74196
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41330
American (AMR)
AF:
0.00
AC:
0
AN:
15256
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3464
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5172
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4812
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10586
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68006
Other (OTH)
AF:
0.000956
AC:
2
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.00000873
Hom.:
0
ExAC
AF:
0.0000414
AC:
5
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Hypertrophic cardiomyopathy Uncertain:1
Apr 29, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces proline, which is neutral and non-polar, with serine, which is neutral and polar, at codon 660 of the MYOM1 protein (p.Pro660Ser). This variant is present in population databases (rs201104206, gnomAD 0.006%). This variant has not been reported in the literature in individuals affected with MYOM1-related conditions. ClinVar contains an entry for this variant (Variation ID: 1383948). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on MYOM1 protein function. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.31
BayesDel_addAF
Uncertain
0.041
T
BayesDel_noAF
Uncertain
0.0
CADD
Pathogenic
26
DANN
Pathogenic
1.0
DEOGEN2
Benign
0.21
T;.;.
Eigen
Pathogenic
0.92
Eigen_PC
Pathogenic
0.88
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Pathogenic
0.98
D;D;D
M_CAP
Benign
0.073
D
MetaRNN
Pathogenic
0.83
D;D;D
MetaSVM
Uncertain
-0.19
T
MutationAssessor
Uncertain
2.3
M;.;M
PhyloP100
10
PrimateAI
Benign
0.47
T
PROVEAN
Pathogenic
-5.3
D;.;D
REVEL
Uncertain
0.55
Sift
Uncertain
0.0030
D;.;D
Sift4G
Uncertain
0.0090
D;D;D
Polyphen
1.0
D;.;D
Vest4
0.81
MutPred
0.59
Loss of catalytic residue at P660 (P = 0.0055);.;Loss of catalytic residue at P660 (P = 0.0055);
MVP
0.85
MPC
0.63
ClinPred
0.90
D
GERP RS
5.9
Varity_R
0.54
gMVP
0.62
Mutation Taster
=72/28
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs201104206; hg19: chr18-3141984; API